Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO Page 1 # **Endodontic Diagnostic Radiography** 1 # **Outline** - **Principles of Radiography** - **Positioning Devices** - **Radiographic Interpretation** - **Tube Shift Techniques** - **Endodontic “Working” Radiography** - **Specific Techniques for Each Tooth** 2 $2^{nd}$ Year DMD - 2023 Page 1 Three endodontic radiographs showing diagnostic stages. # **Endodontic Diagnostic Radiography** # **Outline** - **Principles of Radiography** - **Positioning Devices** - **Radiographic Interpretation** - **Tube Shift Techniques** - **Endodontic “Working” Radiography** - **Specific Techniques for Each Tooth** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 3 **Outline** * Principles of Radiography * Positioning Devices * Radiographic Interpretation * Tube Shift Techniques Endodontic Radiography 4 * **Radiography is used in endodontics for:** * Diagnosis * Pre-operative assessment of root canal anatomy * “Working” films * Technical assessment of treatment * Review healing and tissue responses - * After endodontic treatment * After surgery * After trauma $2^{nd}$ Year DMD - 2023 Page 2 # **Uses of Radiography in Endodontics** - Diagnosis - Pre-operative assessment of root canal anatomy - “Working” films - ==To establish the working length of the root canal.== - ==To check the fit of the master gutta-percha point.== - Technical assessment of treatment - Review healing and tissue responses - - After endodontic treatment - After surgery - After trauma Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 5 **Radiography Techniques** - **Parallel technique** - **Bisecting angle technique** 6 2$^{nd}$ Year DMD - 2023 Page 3 Diagram illustrating the geometry of diverging and parallel central ray beams in dental radiography, showing distortion and accurate image formation. # **Radiography Techniques** > [!info] > The geometry of the X-ray beam, the object (tooth), and the sensor/film position dramatically affects the resulting image. An incorrect setup can lead to significant distortion. > - **Elongation:** ==A shallow vertical angle can make the tooth appear much longer than its actual length (e.g., a 13mm tooth appearing as 19mm).== > - **Foreshortening:** ==A steep vertical angle (from a more apical direction) can make the tooth appear much shorter (e.g., a 13mm tooth appearing as 9mm).== - **Parallel technique** - **Bisecting angle technique** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO Page 4 2nd Year DMD - 2023 7 **Parallel Technique** 8 **Bisecting Angle Technique** Diagram illustrating the parallel technique for dental radiography and a resulting radiograph image. Diagram illustrating the bisecting angle technique for dental radiography and a resulting radiograph image. ## **Parallel Technique** > [!note] > In the parallel technique, the film or sensor is placed parallel to the long axis of the tooth being radiographed. The central X-ray beam is then directed perpendicularly (at 90 degrees) to both the tooth and the sensor. > - **Ideal Image Characteristics (Upper Posterior):** > - ==The buccal roots of premolars and molars appear slightly shorter than the palatal roots.== > - ==The palatal root of a molar is ideally positioned between the two buccal roots.== ## **Bisecting Angle Technique** > [!note] > This technique is used when the sensor cannot be placed parallel to the tooth. The sensor is placed at an angle to the tooth's long axis. The operator must then visualize an imaginary line that bisects the angle formed by the tooth and the sensor. The central X-ray beam is directed perpendicularly to this imaginary bisecting line. > - **Image Characteristics (Upper Posterior):** > - ==The buccal roots of premolars and molars appear significantly shorter than the palatal roots.== > - ==The zygoma is often superimposed over the apex of the palatal root of the maxillary first molar.== Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Parallel -v- Bisecting Angle** 9 **Effect of radiographic technique** **upon prediction of tooth length** **in intraoral radiography** Bhakdinaronk A, Manson-Hing LR. **OS:OM:OP 1981; 51: 100-107.** 10 2$^{\text{nd}}$ Year DMD - 2023 Page 5 ## **Parallel vs. Bisecting Angle** > [!info] > Changing the radiographic technique results in a different visual representation of the same anatomical structures. The parallel technique generally provides a more geometrically accurate image compared to the bisecting angle technique. ### **Effect of radiographic technique upon prediction of tooth length in intraoral radiography** Bhakdinaronk A, Manson-Hing LR. **OS:OM:OP 1981; 51: 100-107.** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Radiographic technique and prediction of tooth length** **Bhakdinaronk & Manson-Hing 1981** * **Used four different film holders:** * **Rinn XCP** * **Styrofoam bite block** * **Haemostat with bite block** * **Patient’s finger** 11 **Radiographic technique and prediction of tooth length** **Bhakdinaronk & Manson-Hing 1981** * **Used four different film holders:** * **Rinn XCP** * **Styrofoam bite block** * **Haemostat with bite block** * **Patient’s finger** * **Compared Parallel and Bisecting Angle techniques** * **Compared radiographic tooth length to the actual** **tooth length measured after extraction** 12 2nd Year DMD - 2023 Page 6 ### **Study: Radiographic technique and prediction of tooth length (Bhakdinaronk & Manson-Hing 1981)** - **Methodology:** - **Used four different film holders:** - Rinn XCP - Styrofoam bite block - Haemostat with bite block - Patient’s finger - **Compared Parallel and Bisecting Angle techniques** - **Compared radiographic tooth length to the actual tooth length measured after extraction** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Radiographic technique and prediction of tooth length** **Bhakdinaronk & Manson-Hing 1981** + **Most accurate to least accurate:** | | | |---|---| | **Rinn XCP** | | | **Styrofoam bite block** | **+ Parallel** | | **Haemostat with bite block** | **Technique** | | **Patient’s finger** | | + **Patient’s finger technique had the greatest amount of film bending** **Radiographic technique and prediction of tooth length** **Bhakdinaronk & Manson-Hing 1981** + **Parallel technique with the RINN XCP film holder was the most accurate technique** + **Beam guiding film holders were more accurate than techniques without guidance** + **Film holders with backing were more reliable than holders with no support for the film** 2nd Year DMD - 2023 Page 7 - **Results:** - **Most accurate to least accurate:** <table> <tr> <td><strong>Rinn XCP</strong></td> <td rowspan="4" style="vertical-align:middle;"><strong>+ Parallel Technique</strong></td> </tr> <tr> <td><strong>Styrofoam bite block</strong></td> </tr> <tr> <td><strong>Haemostat with bite block</strong></td> </tr> <tr> <td><strong>Patient’s finger</strong></td> </tr> </table> - **Patient’s finger technique had the greatest amount of film bending** - **Conclusions:** - ==The **parallel technique** consistently produced more accurate images than the bisecting angle technique across all holder types.== - **Parallel technique with the RINN XCP film holder was the most accurate technique** - **Beam guiding film holders were more accurate than techniques without guidance** - **Film holders with backing were more reliable than holders with no support for the film** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO Radiographic technique and prediction of tooth length Bhakdinaronk & Manson-Hing 1981 * **All techniques and all tooth types had some magnification of the image** * **Magnification range: 6.4% - 16.2%** * **Average: 10% with the parallel technique** 15 16 2$^{\text{nd}}$ Year DMD - 2023 Page 8 A diagram illustrating the central ray and the central axis of the tooth with apparatus for radiographic technique. - **Magnification:** - **All techniques and all tooth types had some magnification of the image** - **Magnification range: 6.4% - 16.2%** - **Average: 10% with the parallel technique** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 17 18 2nd Year DMD - 2023 Page 9 Diagram illustrating the concept of X-ray beam divergence and resulting image size, showing a point source and a cylindrical beam with divergent rays. Diagram showing two illustrations of X-ray beam divergence. The upper illustration shows a narrower beam with less divergence, while the lower illustration shows a wider beam with greater divergence. Square and circular objects are shown above the upper tube representation. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 19 20 $2^{nd}$ Year DMD - 2023 Page 10 A diagram illustrating the difference between a smaller and a larger focal spot in an x-ray tube, showing the resulting beam spread. A diagram showing the X-ray tube head, indicating the distance between the focal spot and the object being imaged, illustrating the Inverse Square Law principle. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 21 **Parallel Technique** * **Parallel technique is more accurate than the bisecting angle technique** * **BUT still have approx. 10% magnification** * **Since the x-rays come from a "point source"** * **Can minimise with rectangular collimation and long cones** 22 2nd Year DMD - 2023 Page 11 Diagram showing the principle of the parallel technique with a representation of approximate 10% magnification. ## **Parallel Technique Details** - **Parallel technique is more accurate than the bisecting angle technique** - **BUT still have approx. 10% magnification** > [!info] Cause of Magnification > X-rays are generated from a point source within the machine head and diverge as they travel towards the sensor. They do not travel in perfectly parallel lines. This divergence causes the image projected onto the sensor to be larger than the actual object. > [!warning] Clinical Implication > Relying on this magnified measurement for working length can lead to instrumentation beyond the apical foramen, causing damage to periapical tissues. - **Since the x-rays come from a "point source"** - **Can minimise with rectangular collimation and long cones** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 23 **Effect of Magnification** * A tooth that is 21.0 mm long would appear to be about 23.0 mm on the radiograph $\rightarrow$ Since 10% of 21.0 mm is 2.1 mm 24 **Effect of Magnification** 2$^{\text{nd}}$ Year DMD - 2023 Page 12 Radiographs showing the effect of magnification during endodontic procedures. ### **Effect of Magnification** - A tooth that is 21.0 mm long would appear to be about 23.0 mm on the radiograph - Since 10% of 21.0 mm is 2.1 mm Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Radiography Techniques** * Parallel technique * **Modified parallel technique** * Bisecting angle technique 25 **Modified Parallel Technique** * To overcome the 10% magnification that occurs with the parallel technique 26 2$^{\text{nd}}$ Year DMD - 2023 Page 13 ## **Modified Parallel Technique** - To overcome the 10% magnification that occurs with the parallel technique Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Modified Parallel Technique** * To overcome the 10% magnification that occurs with the parallel technique * **Method:** $\rightarrow$ **Increase the vertical angle of the central beam by ~ 15°** 27 **Modified Parallel Technique** * To overcome the 10% magnification that occurs with the parallel technique * **Method:** $\rightarrow$ **Increase the vertical angle of the central beam by ~ 15°** * **Rationale** $\rightarrow$ **Foreshortens the image slightly** 28 $2^{nd}$ Year DMD - 2023 Page 14 - **Method:** - **Increase the vertical angle of the central beam by ~ 15°** - **Rationale** - ==The increased vertical angulation intentionally foreshortens the image by about 10%, compensating for the magnification effect and producing a more dimensionally accurate representation of the tooth's true length.== - **Foreshortens the image slightly** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 29 30 2nd Year DMD - 2023 Page 15 Illustration showing Central Ray angles resulting in image size distortion. The diagram shows the Central ray hitting an object (labelled 10 and 5) angled towards the Film plane. The resulting Image is labelled as 5, indicating linear reduction perpendicular to the film plane. The central ray direction is also indicated by an arrow. Illustration showing the position of the film, tooth (with central axis of teeth indicated) and central rays (in yellow) with subsequent enlargement on the right to show the film and tooth. The aim appears to be to show the effect the film and tooth position have on the image. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 31 <br> <center> <p> <span style="color:yellow;"><b>Outline</b></span> </p> </center> <br> $\diamond$ Principles of Radiography $\diamond$ <span style="color:red;"><b>Positioning Devices</b></span> $\diamond$ Radiographic Interpretation $\diamond$ Tube Shift Techniques Radiographic technique and prediction of tooth length Bhakdinaronk & Manson-Hing 1981 $\diamond$ Most accurate to least accurate: * Rinn XCP * Styrofoam bite block * Haemostat with bite block * Patient's finger <br> <img src="https://i.imgur.com/gTj1j8S.png" alt="+ Parallel Technique"/> <br> $\diamond$ Patient's finger technique had the greatest amount of film bending 32 2<sup>nd</sup> Year DMD - 2023 Page 16 # **Positioning Devices** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO <br> **Rinn XCP Kit** <br></img> <br> 33 <br> **All Radiographic Techniques** **Principles to Follow** * Must be simple to use * Use a positioning device with beam alignment * Must give an accurate image * No film distortion, bending, etc * Stable position with “no hands” needed * Reproducible image over time <br> 34 <br> $2^{nd}$ Year DMD - 2023 Page 17 Image of two different Rinn XCP kits. ## **Rinn XCP Kit** > [!note] > The Rinn XCP (Extension Cone Paralleling) kit is a highly recommended positioning device for diagnostic radiography. It consists of a bite block to hold the sensor, a metal aiming arm, and a plastic aiming ring to guide the X-ray cone. > - ==Modern kits are color-coded (e.g., blue for anterior, yellow for posterior) to simplify assembly. Older versions were all white plastic.== > - ==The device is assembled differently for anterior (vertical sensor orientation) and posterior (horizontal sensor orientation) teeth.== ## **Principles for All Radiographic Techniques** - Must be simple to use - Use a positioning device with beam alignment - Must give an accurate image - No film distortion, bending, etc - Stable position with “no hands” needed - Reproducible image over time Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **All Radiographic Techniques** **Rinn XCP Kit** $\checkmark$ Must be simple to use $\checkmark$ Use a positioning device with beam alignment $\checkmark$ Must give an accurate image (**+ modified parallel tech**) $\checkmark$ No film distortion, bending, etc $\checkmark$ Stable position with “no hands” needed $\checkmark$ Reproducible image over time 35 **Rinn XCP Kit** $\checkmark$ Must be simple to use 36 2$^{\text{nd}}$ Year DMD - 2023 Page 18 Two images showing a patient with a Rinn XCP kit in place and a diagram of the positioning device. ### **Rinn XCP Kit Adherence to Principles** - ✔️ Must be simple to use - ✔️ Use a positioning device with beam alignment - ✔️ Must give an accurate image (**+ modified parallel tech**) - ✔️ No film distortion, bending, etc > [!success] > The rigid backing plate on the bite block prevents the sensor from bending against oral structures like the palate. This avoids the 'stretched' appearance common with bent films, which can create misleading artifacts that mimic pathology. - ✔️ Stable position with “no hands” needed - ✔️ Reproducible image over time Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Rinn XCP Kit** Use a positioning device with beam alignment Rinn XCP Kit image with arrows demonstrating components. 37 **Rinn XCP Kit** Must give an accurate image Radiographic technique and prediction of tooth length Bhakdinaronk & Manson-Hing 1981 * Most accurate to least accurate: * Rinn XCP * Styrofoam bite block * Haemostat with bite block * Patient's finger * Patient's finger technique had the greatest amount of film bending **+ Parallel Technique** 38 2nd Year DMD - 2023 Page 19 - **Use a positioning device with beam alignment** Rinn XCP Kit image with arrows demonstrating components. - **Must give an accurate image** - **Study: Radiographic technique and prediction of tooth length (Bhakdinaronk & Manson-Hing 1981)** - Most accurate to least accurate: - Rinn XCP - Styrofoam bite block - Haemostat with bite block - Patient's finger - Patient's finger technique had the greatest amount of film bending - **+ Parallel Technique** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Rinn XCP Kit** Must give an accurate image Standardized techniques for monitoring healing Andreasen et al **Eur J Orthod 1990** **RINN with the Parallel Technique** Average deviation was only: Tooth length: 0.5 mm Crown width: 0.2 mm 39 **Rinn XCP Kit** No film distortion, bending, etc 40 $2^{nd}$ Year DMD - 2023 Page 20 Image of the Rinn XCP Kit components and a diagram showing a potential issue with traditional radiography vs the parallel technique. - **Must give an accurate image** - **Study: Standardized techniques for monitoring healing (Andreasen et al Eur J Orthod 1990)** - **RINN with the Parallel Technique** - Average deviation was only: - Tooth length: 0.5 mm - Crown width: 0.2 mm - **No film distortion, bending, etc** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 41 42 2nd Year DMD - 2023 Page 21 Radiographs illustrating root anatomy and apical pathology. Two radiographs showing the upper posterior teeth. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Rinn XCP Kit** <div align="center"> <img src="https://i.imgur.com/k9vL6fL.png" alt="A woman with an XCP kit in her mouth for an x-ray, left focusing on the cheek side, and right focusing on the top of the XCP kit."/> </div> 43 <div align="center"> <img src="https://i.imgur.com/vHq9Nf2.png" alt="A woman with an XCP kit in her mouth for an x-ray, left focusing on the cheek side, and right focusing on the top of the XCP kit."/> </div> **Rinn XCP Kit** Reproducible image over time Standardized techniques for monitoring healing Andreasen et al **Eur J Orthod 1990** **RINN with the Parallel Technique** - Average deviation was only: $\to$ **Tooth length:** 0.5 mm $\to$ **Crown width:** 0.2 mm 44 2nd Year DMD - 2023 Page 22 <div align="center"> </div> <div align="center"> </div> - **Reproducible image over time** - **Study: Standardized techniques for monitoring healing (Andreasen et al Eur J Orthod 1990)** - **RINN with the Parallel Technique** - Average deviation was only: - **Tooth length:** 0.5 mm - **Crown width:** 0.2 mm Pre-op, RCF – 1 yr later, and 4 yr Recall radiographic images comparing healing and treatment outcomes over time for tooth 45 Pre-op, RCF – 1 yr later, 2 yr Recall, and 4 yr Recall radiographic images showing longitudinal endodontic evaluation for tooth 46 Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **All Radiographic Techniques** **Rinn XCP Kit** ✔️ Must be simple to use ✔️ Use a positioning device with beam alignment ✔️ Must give an accurate image (**+ modified parallel tech**) ✔️ No film distortion, bending, etc ✔️ Stable position with “no hands” needed ✔️ Reproducible image over time 47 **Rinn XCP Kit** ✔️ Use for ALL diagnostic radiographs (**NOT just Endo!**) ✔️ Use for all post-RCF and follow-up radiographs ✔️ **Use for trauma reviews** ✔️ **Use whenever Rubber Dam is not in place** 48 2nd Year DMD - 2023 Page 24 Image of two different components of the Rinn XCP Kit. ### **Applications of the Rinn XCP Kit** - ✔️ Use for ALL diagnostic radiographs (**NOT just Endo!**) - ✔️ Use for all post-RCF and follow-up radiographs - ✔️ **Use for trauma reviews** - ✔️ **Use whenever Rubber Dam is not in place** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Using the Rinn Holder** **Anterior Teeth** <img src="endodontic_diagnostic_radiography_rinn_holder_anterior_teeth.png" alt="Rinn Holder for Anterior Teeth"> 49 **Using the Rinn Holder** **Upper Anterior Teeth** <img src="rinn_holder_upper_anterior_teeth_diagram.png" alt="Diagram illustrating the use of the Rinn Holder for Upper Anterior Teeth"> 50 2nd Year DMD - 2023 Page 25 ### **Using the Rinn Holder** #### **Anterior Teeth** - ==**Setup:** Use the anterior (blue) bite block, which orients the sensor vertically.== - ==**Correct Cotton Roll Placement:** The manufacturer's diagram often incorrectly shows placing a cotton roll between the bite block and the opposing teeth. This can cause the sensor to tilt, leading to elongation.== - ==**Correct Method:** Place the cotton roll **between the tooth being radiographed and the bite block**. This ensures the sensor remains parallel to the tooth.== #### **Upper Anterior Teeth** > [!tip] > The sensor must be placed far back in the mouth (often in the first molar region) to achieve parallelism due to the curvature of the palate. This increases the object-to-film distance, reinforcing the need for the modified parallel technique to combat magnification. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Using the Rinn Holder** **Upper Anterior Teeth** 51 **Using the Rinn Holder** **Lower Anterior Teeth** 52 2nd Year DMD - 2023 Page 26 Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Using the Rinn Holder** **Posterior Teeth** UL / LR UR / LL 53 **Using the Rinn Holder** **Upper Posterior Teeth** 54 2nd Year DMD - 2023 Page 27 Image showing two configurations of the Rinn Holder for posterior teeth and a close-up of the holder with a sensor. Image showing a diagram of the Rinn Holder placement for upper posterior teeth and a patient receiving the radiograph. #### **Posterior Teeth** - ==**Setup:** Use the posterior (yellow) bite block, which orients the sensor horizontally.== - ==**Important Note:** The aiming ring is offset for posterior shots. The device must be assembled correctly for the specific quadrant (e.g., upper left/lower right vs. upper right/lower left) to avoid a large cone-cut error.== - UL / LR - UR / LL #### **Upper Posterior Teeth** > [!tip] > To achieve parallelism, the sensor is often placed near the midline of the palate, which is its highest point. A cotton roll is placed between the teeth being radiographed and the bite block to stabilize the device and maintain a parallel orientation. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO <div style="background-color: darkblue; padding: 10px;"> <p> <span style="color: yellow;"><b>Using the Rinn Holder</b></span> <img src="crop_2.png" alt="Rinn Holder icon"> </p> <p> <span style="color: limegreen;"><b>Lower Posterior Teeth</b></span> </p> <div style="display: flex;"> <img src="crop_1.png" alt="Diagram showing the placement of the Rinn Holder for lower posterior teeth."> <img src="crop_2.png" alt="Image of a patient's mouth with the Rinn Holder inserted, showing a blue question mark icon indicating uncertainty or a point of focus."> </div> </div> 55 <div style="background-color: darkblue; padding: 10px;"> <p> <span style="color: yellow;"><b>Using the Rinn Holder</b></span> </p> <img src="crop_4.png" alt="Detailed diagram showing the placement and orientation of the Rinn Holder with green arrows pointing to the teeth and the holder assembly."> </div> 56 2$^{\text{nd}}$ Year DMD - 2023 Page 28 #### **Lower Posterior Teeth** > [!tip] > A cotton roll is usually **not necessary** because the floor of the mouth relaxes when the patient closes, providing ample space for the sensor. Occasionally, a cotton roll may be placed on the **opposing arch** to stabilize the bite if there isn't firm contact between the upper teeth and the bite block. <div style="display: flex;"> </div> Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Outline** ♦ Principles of Radiography ♦ Positioning Devices ♦ **Radiographic Interpretation** ♦ Tube Shift Techniques 57 **The Importance of Accurate Radiographs** ✓ Correct Diagnosis 58 2nd Year DMD - 2023 Page 29 # **Radiographic Interpretation** ## **The Importance of Accurate Radiographs** - ✓ Correct Diagnosis > [!example] Examples of Misdiagnosis from Poor Radiographs > - **Example 1:** A poorly angulated and underexposed radiograph suggested a distal periodontal pocket on a molar. A subsequent, well-angulated radiograph taken with a Rinn holder revealed no pocket, but rather an open mesial crown margin that was the true cause of the patient's pulpitis. > - **Example 2:** A radiograph of an anterior tooth taken with a horizontally-oriented and bent film created the false appearance of a developmental root defect. A correctly taken radiograph with a vertically-oriented film showed normal anatomy. > - **Example 3:** A series of non-standardized radiographs taken to monitor traumatized teeth showed huge variations in apparent tooth length. This made estimating the working length for subsequent root canal treatment impossible, leading to initial instrumentation far beyond the apex. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 59 60 2nd Year DMD - 2023 Page 30 Two radiographs shown with red arrows pointing to specific areas: one pointing to a radiolucency periapical to a restored tooth, and the other pointing to a radiolucent area in the furcation of a posterior tooth. Two periapical radiographs showing anterior mandibular teeth; one radiograph has a red arrow pointing to a radiolucent area at the apex of one of the teeth. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO <img src="Endodontic Diagnostic Radiography - Image 1" alt="Radiographic images showing root canal treatment and possible pathology indicated by red arrows." /> 61 62 2$^{\text{nd}}$ Year DMD - 2023 Page 31 Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Size 0 - 22 x 35 mm - 770 mm²** **Size 1 - 24 x 40 mm - 960 mm²** **Size 2 - 31 x 41 mm - 1271 mm²** 63 **Recommended Film Sizes** **Size 2 - standard film used for PA's** **Size 1 - narrow arches, anterior teeth** **Size 4 - occlusal views** 64 2$^{nd}$ Year DMD - 2023 Page 32 Three radiographs labeled 2, 1, and 0 in ascending order of size, and an outline of a size 4 film. ## **Recommended Film Sizes** - **Size 0 - 22 x 35 mm - 770 mm²** > [!warning] > The use of Size 0 film is very limited as it captures a small area, providing minimal diagnostic information. - **Size 1 - 24 x 40 mm - 960 mm²** - **Size 2 - 31 x 41 mm - 1271 mm²** - **Size 2 - standard film used for PA's** - ==Should be used whenever possible for posterior teeth (horizontally) and upper anteriors (vertically).== - **Size 1 - narrow arches, anterior teeth** - ==Often preferable for the **lower anterior region** where the arch is narrow. It has the same length as a size 2 but is narrower.== - **Size 4 - occlusal views** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **The Importance of** **Accurate Radiographs** **Endodontics** **Root Canal Length Estimation** 65 66 2$^{\text{nd}}$ Year DMD - 2023 Page 33 Four radiographic images showing teeth with pink lines indicating the estimated root canal length. ## **The Importance of Accurate Radiographs** - **Endodontics** - **Root Canal Length Estimation** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 67 **Radiographic Interpretation** * Accuracy of interpretation affected by many factors * Film type & exposure time * Technique & angulations used * Standard of developing 68 2$^{\text{nd}}$ Year DMD - 2023 Page 34 Multiple periapical radiographs showing different angulations and interpretations of root canal working length/obturation. Vertical lines indicate position/length; horizontal arrows point to areas of interest. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO Page 35 2nd Year DMD - 2023 # Radiographic Interpretation * **Accuracy of interpretation affected by many factors** * Film type & exposure time * Technique & angulations used * Standard of developing * Endodontic file size used # Radiographic Interpretation * **Accuracy of interpretation affected by many factors** * **Superimposition of other structures** $\rightarrow$ Bone processes, roots, canals, etc * Foramen position with respect to root apex $\rightarrow$ **Mesial / Distal** or **Buccal / Lingual** 69 70 ## **Factors Affecting Interpretation Accuracy** - Film type & exposure time - Technique & angulations used - Standard of developing - Endodontic file size used - **Superimposition of other structures** - ==The mental foramen or incisive foramen can be superimposed over a root apex, mimicking a periapical lesion.== - Bone processes, roots, canals, etc - Foramen position with respect to root apex - **Mesial / Distal** or **Buccal / Lingual** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 71 **Radiographic Interpretation** * Accuracy of interpretation affected by many factors * Density of bone → Trabeculae, cortical plate * Amount of bone that has been resorbed → ? **How much is required** 72 **Radiographic Interpretation** * How much bone loss is required before a radiolucency can be reliably detected on a PA radiograph ?? * ■ Cortical plate involved → Bender & Seltzer 1961(a) * ■ **Junctional trabeculae involved** → Bender & Seltzer 1961(b) 2$^{\text{nd}}$ Year DMD - 2023 Page 36 - Density of bone - Trabeculae, cortical plate - Amount of bone that has been resorbed - ? **How much is required** ### **Bone Loss Required for Radiographic Detection** - How much bone loss is required before a radiolucency can be reliably detected on a PA radiograph ?? - Cortical plate involved - Bender & Seltzer 1961(a) - **Junctional trabeculae involved** - Bender & Seltzer 1961(b) > [!info] > The actual amount likely varies between patients depending on their individual bone anatomy. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO # **Radiographic Interpretation** * How much bone loss is required before a radiolucency can be reliably detected on a PA radiograph ?? * Cortical plate involved * Bender & Seltzer 1961(a) * **Junctional trabeculae involved** * Bender & Seltzer 1961(b) * **Cancellous bone involved** * Shoha et al 1974, Pitt Ford 1984 * **Lamina dura destroyed** * Lee & Messer 1986, Barbat & Messer 1998 73 # **Radiographic Interpretation** * Poor correlation between radiographic interpretation and the histological findings * Bender & Seltzer 1964, Pitt Ford 1984 * **Lesion always larger histologically than on radiograph** * Bender & Seltzer 1964 74 2nd Year DMD - 2023 Page 37 - **Cancellous bone involved** - Shoha et al 1974, Pitt Ford 1984 - **Lamina dura destroyed** - Lee & Messer 1986, Barbat & Messer 1998 ### **Correlation with Histological and Surgical Findings** - Poor correlation between radiographic interpretation and the histological findings - Bender & Seltzer 1964, Pitt Ford 1984 - **Lesion always larger histologically than on radiograph** - Bender & Seltzer 1964 > [!example] Balloon Analogy > Think of a balloon. The radiograph primarily shows the densest part of the lesion (the middle of the balloon), while the less-demineralized peripheral areas are obscured by the surrounding bone. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO # **Radiographic Interpretation** * Poor correlation between radiographic interpretation and the histological findings * Bender & Seltzer 1964, Pitt Ford 1984 * **Lesion always larger histologically than on radiograph** * Bender & Seltzer 1964 * Lesion always **larger surgically than on radiograph** * Farman et al 1998, Scarfe et al 1999 75 76 # **Outline** * Principles of Radiography * Positioning Devices * Radiographic Interpretation * **Tube Shift Techniques** $2^{nd}$ Year DMD - 2023 Page 38 - Lesion always **larger surgically than on radiograph** - Farman et al 1998, Scarfe et al 1999 # **Tube Shift Techniques** > [!note] > Tube shift techniques involve changing the angle of the X-ray beam to gain a quasi-three-dimensional perspective and separate superimposed structures. Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Tube Shift Techniques** * **Vertical Shift** * **Horizontal shift** 77 **Tube Shift Techniques** * **Vertical Shift** * Increased angle * Decreased angle * **Horizontal shift** * Mesial * Distal 78 2$^{nd}$ Year DMD - 2023 Page 39 - **Vertical Shift** - Increased angle - Decreased angle - **Horizontal shift** - Mesial - Distal Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Tube Shift Techniques** $\diamond$ **Vertical Shift** - $\quad$ Increased angle - $\quad$ Decreased angle 79 **Tube Shift Techniques** $\diamond$ **Vertical Shift** - $\quad$ Increased angle - $\quad$ Decreased angle 80 2$^{\text{nd}}$ Year DMD - 2023 Page 40 ## **Vertical Shift** - Increased angle - Decreased angle Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO | | | |---|---| | 2nd Year DMD - 2023 | Page 41 | ## **Tube Shift Techniques** Vertical Shift - **Decreased angle** $\rightarrow$ **elongates the image** - **NO diagnostic value** - **NO practical value** 81 82 Radiographs demonstrating vertical shift - **Decreased angle** - **elongates the image** - **NO diagnostic value** - **NO practical value** > [!danger] > This is never done intentionally. Endodontic Diagnostic Radiography | W/Prof. Paul V. Abbott AO <br clear="all"> # **Tube Shift Techniques** Vertical shifts * **Increased angle** → **15º vertical shift** * **Modified parallel technique** * **Provides more apical detail and definition** 83 # **Tube Shift Techniques** Vertical shifts * **Increased angle** → **15º vertical shift** * **Modified parallel technique** * **Provides more apical detail and definition** → **Occlusal views** * **Esp. useful for trauma diagnosis** * **Root Fractures & Lateral Luxation** 84 2\textsuperscript{nd} Year DMD - 2023 | Page 42 - **Increased angle** - **15º vertical shift** - **Modified parallel technique** - **Provides more apical detail and definition** - **Occlusal views** - **Esp. useful for trauma diagnosis** - **Root Fractures & Lateral Luxation** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Root Fractures** 85 **Lateral Luxation** 86 $2^{nd}$ Year DMD - 2023 Page 43 A comparison of two different radiographic approaches (periapical and occlusal) to detect root fractures, showing how the angle of the x-ray beam affects the image. Comparison of periapical and occlusal radiographic techniques for diagnosing lateral luxation, showing different angles of projection and resulting images. ### **Root Fractures** ### **Lateral Luxation** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 87 **Section from Occlusal film** 88 **Tube Shift Techniques** Horizontal shifts * **Mesial** * **Distal** 2nd Year DMD - 2023 Page 44 Multiple radiographic images with a section from an occlusal film. **Section from Occlusal film** ## **Horizontal shifts** > [!tip] The SLOB Rule > The **SLOB rule (Same Lingual, Opposite Buccal)** is used for interpretation. When the tube head is shifted, the object that is positioned more **L**ingually will appear to move in the **S**ame direction as the tube head shift. The object that is more **B**uccally will appear to move in the **O**pposite direction. - **Mesial** - **Distal** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Tube Shift Techniques** **Horizontal shifts** * **Mesial** * **Distal** - Used to separate objects that are otherwise superimposed over each other - Can help to indicate the “3rd dimension” 89 90 2nd Year DMD - 2023 Page 45 Diagram illustrating Mesial, Straight View, and Distal tube shift techniques showing the relative positions of the target objects (Buccal and Lingual) relative to the film and central ray (CR). - Used to separate objects that are otherwise superimposed over each other - Can help to indicate the “3rd dimension” ### **Applications of Horizontal Shifts** - ==**Separating Canals:** On a straight-on view of a lower incisor or the mesial root of a mandibular molar, two canals (buccal and lingual) will be superimposed. A mesial or distal shift will separate them on the image, allowing for their identification.== - ==**Separating Roots:** A straight-on view of a maxillary molar places the palatal root between the two buccal roots. A mesial shift will move the palatal (lingual) root mesially, while a distal shift will move it distally.== - ==**Differentiating Anatomy from Pathology:** A tube shift can move an anatomical structure (like the incisive foramen) off of a root apex, confirming that a suspected radiolucency is not endodontic pathology but rather a superimposed normal feature.== - ==**Identifying Missed Anatomy or Problems:** A tube shift can reveal previously unseen features, such as a third canal in a premolar or a mid-root perforation that is hidden on a straight-on view.== Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO **Straight View** | Mesial | Distal | | :---: | :---: | | | | 91 92 2$^{\text{nd}}$ Year DMD - 2023 | Page 46 ### **Straight View** | Mesial | Distal | | :---: | :---: | | | | Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO 93 94 2nd Year DMD - 2023 Page 47 Radiographic comparison showing a periapical radiolucency. Radiographic comparison showing a periapical radiolucency with an arrow pointing to the apex. # **Endodontic Diagnostic Radiography** ### **W/Prof. Paul V. Abbott AO** Endodontic Diagnostic Radiography W/Prof. Paul V. Abbott AO <p align="center"> <img src="image1.jpg" alt="Two small dental radiographs, one labelled Mesial and one labelled Distal" /> </p> Mesial Distal 95 96 <div style="background-color: navy; color: white; padding: 20px;"> <h2 style="text-align: center; color: yellow;">Outline</h2> <ul> <li><font color="#FF0000"> Principles of Radiography</font></li> <li><font color="#FF0000"> Positioning Devices</font></li> <li><font color="#FF0000"> Radiographic Interpretation</font></li> <li><font color="#FF0000"> Tube Shift Techniques</font></li> <li><font color="#FF0000"> Endodontic “Working” Radiography</font></li> <li><font color="#FF0000"> Specific Techniques for Each Tooth</font></li> </ul> </div> 2<sup>nd</sup> Year DMD - 2023 Page 48 <p align="center"> </p> Mesial Distal ## **Radiographic Reporting** > [!todo] > The process of radiographic interpretation is not complete until a formal report is written and included in the patient's clinical records. It is not enough to simply look at the image and make a decision; the observations must be documented. ## **Outline** - Principles of Radiography - Positioning Devices - Radiographic Interpretation - Tube Shift Techniques - Endodontic “Working” Radiography - Specific Techniques for Each Tooth > [!note] > This lecture explores the principles and techniques of diagnostic radiography in endodontics. While some concepts apply to working radiographs taken during treatment (which have been discussed previously), the focus here is on the diagnostic phase. [[L16 Endo Diagnostic radio.pdf#page=1|L16 Endo Diagnostic radio, p.1]] [[L16 Endo Diagnostic radio.pdf#page=2|L16 Endo Diagnostic radio, p.2]] [[L16 Endo Diagnostic radio.pdf#page=3|L16 Endo Diagnostic radio, p.3]] [[L16 Endo Diagnostic radio.pdf#page=4|L16 Endo Diagnostic radio, p.4]] [[L16 Endo Diagnostic radio.pdf#page=5|L16 Endo Diagnostic radio, p.5]] [[L16 Endo Diagnostic radio.pdf#page=6|L16 Endo Diagnostic radio, p.6]] [[L16 Endo Diagnostic radio.pdf#page=7|L16 Endo Diagnostic radio, p.7]] [[L16 Endo Diagnostic radio.pdf#page=8|L16 Endo Diagnostic radio, p.8]] [[L16 Endo Diagnostic radio.pdf#page=9|L16 Endo Diagnostic radio, p.9]] [[L16 Endo Diagnostic radio.pdf#page=10|L16 Endo Diagnostic radio, p.10]] [[L16 Endo Diagnostic radio.pdf#page=11|L16 Endo Diagnostic radio, p.11]] [[L16 Endo Diagnostic radio.pdf#page=12|L16 Endo Diagnostic radio, p.12]] [[L16 Endo Diagnostic radio.pdf#page=13|L16 Endo Diagnostic radio, p.13]] [[L16 Endo Diagnostic radio.pdf#page=14|L16 Endo Diagnostic radio, p.14]] [[L16 Endo Diagnostic radio.pdf#page=15|L16 Endo Diagnostic radio, p.15]] [[L16 Endo Diagnostic radio.pdf#page=16|L16 Endo Diagnostic radio, p.16]] [[L16 Endo Diagnostic radio.pdf#page=17|L16 Endo Diagnostic radio, p.17]] [[L16 Endo Diagnostic radio.pdf#page=18|L16 Endo Diagnostic radio, p.18]] [[L16 Endo Diagnostic radio.pdf#page=19|L16 Endo Diagnostic radio, p.19]] [[L16 Endo Diagnostic radio.pdf#page=20|L16 Endo Diagnostic radio, p.20]] [[L16 Endo Diagnostic radio.pdf#page=21|L16 Endo Diagnostic radio, p.21]] [[L16 Endo Diagnostic radio.pdf#page=22|L16 Endo Diagnostic radio, p.22]] [[L16 Endo Diagnostic radio.pdf#page=23|L16 Endo Diagnostic radio, p.23]] [[L16 Endo Diagnostic radio.pdf#page=24|L16 Endo Diagnostic radio, p.24]] [[L16 Endo Diagnostic radio.pdf#page=25|L16 Endo Diagnostic radio, p.25]] [[L16 Endo Diagnostic radio.pdf#page=26|L16 Endo Diagnostic radio, p.26]] [[L16 Endo Diagnostic radio.pdf#page=27|L16 Endo Diagnostic radio, p.27]] [[L16 Endo Diagnostic radio.pdf#page=28|L16 Endo Diagnostic radio, p.28]] [[L16 Endo Diagnostic radio.pdf#page=29|L16 Endo Diagnostic radio, p.29]] [[L16 Endo Diagnostic radio.pdf#page=30|L16 Endo Diagnostic radio, p.30]] [[L16 Endo Diagnostic radio.pdf#page=31|L16 Endo Diagnostic radio, p.31]] [[L16 Endo Diagnostic radio.pdf#page=32|L16 Endo Diagnostic radio, p.32]] [[L16 Endo Diagnostic radio.pdf#page=33|L16 Endo Diagnostic radio, p.33]] [[L16 Endo Diagnostic radio.pdf#page=34|L16 Endo Diagnostic radio, p.34]] [[L16 Endo Diagnostic radio.pdf#page=35|L16 Endo Diagnostic radio, p.35]] [[L16 Endo Diagnostic radio.pdf#page=36|L16 Endo Diagnostic radio, p.36]] [[L16 Endo Diagnostic radio.pdf#page=37|L16 Endo Diagnostic radio, p.37]] [[L16 Endo Diagnostic radio.pdf#page=38|L16 Endo Diagnostic radio, p.38]] [[L16 Endo Diagnostic radio.pdf#page=39|L16 Endo Diagnostic radio, p.39]] [[L16 Endo Diagnostic radio.pdf#page=40|L16 Endo Diagnostic radio, p.40]] [[L16 Endo Diagnostic radio.pdf#page=41|L16 Endo Diagnostic radio, p.41]] [[L16 Endo Diagnostic radio.pdf#page=42|L16 Endo Diagnostic radio, p.42]] [[L16 Endo Diagnostic radio.pdf#page=43|L16 Endo Diagnostic radio, p.43]] [[L16 Endo Diagnostic radio.pdf#page=44|L16 Endo Diagnostic radio, p.44]] [[L16 Endo Diagnostic radio.pdf#page=45|L16 Endo Diagnostic radio, p.45]] [[L16 Endo Diagnostic radio.pdf#page=46|L16 Endo Diagnostic radio, p.46]] [[L16 Endo Diagnostic radio.pdf#page=47|L16 Endo Diagnostic radio, p.47]] [[L16 Endo Diagnostic radio.pdf#page=48|L16 Endo Diagnostic radio, p.48]]